Abstract:In the present experiment, the correlations between the changes of isozymes and fertility under different natural conditions, different day-light lengths and different temperature treatments were studied by means of the pollen fertility index, using the photoperiod-temperature sensitive genie male-sterile lines (NongKen58S, Shuang8-2S, N9RS). At the same time, the linkage relationships between isozyme genes and sterility genes were tested. The results indicated that there were close relationships between Adh-1, Est-3 and sterility. In the case of fertility and sterility, both of the loci expressed null alleles and active alleles respectiv -ely. One of sterility genes Jinked to Adh-1 with a recombination value of 0, another gene linked to Cat-1 with a recombination value of 29 percent.

Abstract:The basic structure of mature chloroplasts of leaves of the wild rice (Oryza sativa L. f. spontanca) was found to be similar to that of cultivated rice Oryza saliva L. ). The chloroplasts of cultivated rice had more grana, more grana lamellae and showed greater electron density of the cytoplasm than those of the wild rice species.The chloroplasts of wild rice had more stroma lamellae and more osmiophilic bodies than those of the cultivated rice.The chloroplasts of cultivated rice which contained a number of starch granules were adjacent to mitochondria and peroxisomes. Starch granules were observed in the chloroplast of annual wild rice, but not in the perennial wild rice. These results support the theory that the rice line of Southern China might have originated from O. sativa L. f. spontanca and showed that the cultivated rice was more closely relation to the annual wild rice than to the perennial wild rice.

Abstract:From the seedling stage, N98S/Teqing, a two-line hybrid rice, exhibited heterosis in morphological and physiological characters.In yield components,the panicles per mu and filled grains per panicle of this hybrid rice showed 10. 52% and 31. 25% mid-parent heterosis respectively. It also presented heterosis over HuaYougui 44, a check strain of three-line indica hybrid rice , in panicles per mu by 15. 92% and 1000-grain weight by 5. 22%. The theoretical yield showed 11% heterobeltosis and 19. 26% standard heterosis. proving that N98S/ Teqing has a potential for increased yield.

Abstract:Studies on the longevity of the seeds of three rice lines and their F1 hybrids with different moisture contents were conducted. This study found that: the safe moisture contents of male sterile lines and F1hybrids had decreased by 2% as compared with 13% for the maintainer lines and restorer lines, which is the upper limit of national standard moisture content for conventional rice varieties; The seed moisture content of the male sterile line and F1 hybrids is just about 11%, and the variation in longevity tends to show a typical contra-S - shaped survival curve. As the sprouting rate decreased to 80% the survival curve descended rapidly. According to the rules of the typical survival curve, we can set up several new equations to predict seed longvity.

Abstract:Using six varieties of indica rice as experimental materials, the study results indicated that sorbitol added to Ls medium was able to promote the growing of callus and improve its differentiation in serial subcultures. For different varieties of indica rice the growing capacity of callus and plant regeneration displayed evident varietal specificities in later stages of subcultures. After adding phytohormone with different concentrations into the differentiating medium, there were obvious disparities in differentiation effects on the organ indicated.Synchronized growing of root and bud was favoured when-kinetin (KT)and naphthalene acetic acid (NAA) were present in the ratio of 5 : 1.

Abstract:Using the inoculation method of injecting wheat scab spores into a single floret in the middle of a wheat spike for three years in succession, three resistance criteria (the period from inoculation to the disease spreading to the rachis, the number of diseased spikelets, the number of diseased internodes on the rachis) were studied. The results indicated that high resistance, medium resistance and Susceptibility could be more clearly differentiated by the number of diseased spikelets, which proved to be the most consistent criterion. We could make a more accurate evaluation of the varietal resistance relying mainly on the number of diseased spikelets while taking the number of diseased internodes on the rachis as an auxiliary index.

Abstract:The frequency of occurence of white - yellow stripes on plant leaves,developed from irradiated maize seeds containing lemon - white gene (Lw1/lw1), was used as a criterion in comparing the mutagenic effects of high LET heavy ion beam and low LET radiation. Dose - response curves for 20Ne,40Ar,56Fe ion beam, and 60Co gamma rays were linear. The RBE for neon, argon and iron beam, when compared with 60Co gamma rays, were 2. 02, 8. 31 , and 12. 45, respectively. Lemon -white gene nmtalion was observed in inbred plants in the second generation. Electron microscope observation showed that both the structure and the number of chloroplasts in mesophy Is of white -yellow stripes were significantly altered.

Abstract:An experiment was conducted with a corn hybrid, Guiding 1, using different sowing dates from Feb. to Sept. during the years of 1988 to 1989 in Guangzhou. The result showed that the effect of different sowing dates on total growth period, grain yield, plant height and the height from soil surface to the first ear were more significant than that on the number of leaves per plant and the ratio of the height from soil surface to the first ear to plant height. Compared with the corn sowing dates from April to August, the corn sowed in Feb. , March and Sept. had longer total growth period. The yields of different sowing dates from March to the first ten days of April and July to Sept. were higher than the yields of sowing dates in May and June. The total growth period of corn was affected mainly by temperature. The growth and development of corn was retarded at lower temperatures, and promoted at higher temperatures. The yield was affected by temperature. Among yield components, the grain weight and the number of grains on one row of an ear varied widely, and they correlated with the yield most closely.

Abstract:水稻、玉米和花生3种作物的叶片水势的日变化,都以黎明最高,上午较剧降低,午后13～14时最低,傍晚和晚上逐渐回升,黎明又出现最高值。水稻叶片水势日变化与温度日变化,呈极显著负相关。不同叶位的叶片水势,以最顶部展开叶最高,随着急剧下降,展开叶下一叶及下位叶的水势较低,变化与叶位次序无关。同一种作物,不同植株之间的叶片水势差异甚大。用水势仪(HR——33T DEW POINT MICROVOLTMETER)法和小液流法对5种植物叶片水势进行测定比较,结果基本一致。

Abstract:The results obtained from using different nitrogen level in field expriments were as follows: Nodulation and development of peanuts were inhibited by inorganic nitrogen fertilizer. When applying 2. 5 kg net nitrogen per mu, the number and dry weight of nodules per peanut plant were both notably inhibited (P< 0. 05), and nodulation date was later than that of untreated control. The nitrogen supply to the plants varied with different nitrogen levels. Before the podding slage .such as the seedling stage and pod-pin stage, the nitrogen content of plant body was increased by increasing the amount of applied nitrogen fertilizer. After the podding stage, that is, the maturation stage, the nitrogen content of the plant was increased as the number and dry weight of nodules per plant increased. Nitrogen content of plant was highest in the podding stage, but with excessive nitrogen fertilizer, the nitrogen content of the plant was highest in the pod-pin stage. The yield of peanuts was highest in the N2.5 treament group and lowest in the N10.

Abstract:Experiments were carried out with carnation by using ethylene releasers as growth regulators suppiemellted in the media. Results showed that ACC, the immediate precursor of ethylene, exhibited significant effect on preventing the vitrification of in vitro culture of carnation, and obtaining full - grown plantlets without subculture. The induction frequency of normal planllets was 98%. A compact stem and leaf and good root system was observd in in vitro culture. Under microscopical examination, closely arranged cells and well developed sclerenchyma tissue were found in cross sections of the stem. Biochemical analysis revealed that the dry matter and chlorophyll contents were higher than those of vitrified ones by 1.7 and 5. 5 times, respectively. The growth of plantlets induced by CEPA were similar to those by ACC. The quantity of ethylene released in the culture tubes where the media was supplemented with ACC or CEPA was found to be much higher than that in the control lubes, implying that ethylene had good effect on vitrification prevention.

Abstract:应用水汽蒸馏,气相色谱,气相色谱—质谱—计算机联用等方法分析了姜花鲜花的香气成分。在分离的63个色谱峰中鉴定了33种化合物,并测定了其相对含量。其主要成分是:香叶烯醇,芳樟醇,顺式石竹烯,β-萜品醇,苯申酸苯甲酯,2-甲氧基-4(1-甲烯基)苯酚,摩珞烯,癸烷,2、6-二叔丁基-4甲基苯酚,萘,甲基萘,β-法呢烯等。

Abstract:Ten types of soil were collected from Guangdong Province in South China and planted to Graham stylo (Stylosanthes guianensiss cv. Graham) in pots so that nutrient requirements could be assessed. The main results of the experiment are as follows: The response of the stylo to P fertilizer in many soils was good, but P fertilizer had no significant effect on stylo in the soil where available P was higher than 5 ppm. or available P was ranging from 3 to 5 ppm and the soil pH was greater than 7. Liming on high pH (>7) soil would decrease the availability of P. After soil P deficiency was corrected. K fertilizer was good for stylo growth and achieved significant effect on dry matter production, but it usually reduced crude protein content and caused luxury absorbption of K. P fertilizer could reverse the situation. The stylo in early growth stage showed no response to K fertilizer. K fertilizer had an accumulative effect on the late stage of the stylo. Liming in soil with the pH lower than 5 such as Quaternary red soil and granite soil had highly positive effect on the growth of the stylo and liming in soil with the pH greater than 7 such as limestone soil or purple sandy shale soil had highly negative effect on stylo growth. Liming in soils with the pH ranging from 5 to 7 had no significant effect. Liming. P. K fertilizing might affect the availability of trace elements such as B. Mo etc..